How Pool Algaecide Works: Complete Chemistry Guide 2026
I replaced three different algaecides in two months, my 20,000-gallon pool still gets green spots weekly, AND my perfect chlorine levels aren't preventing anything. I've tried copper-based and polyquat algaecides, but I'm curious about the actual chemistry behind how these products work to kill algae.
My current chlorine levels are around 2-3 ppm and pH is 7.4, but I still get green spots forming on the walls every few weeks. The pool guy says algaecides work differently than chlorine, but he couldn't explain exactly how. I'd love to understand the science behind what's happening at the cellular level when algaecide contacts algae, and whether I should be relying more on higher chlorine levels or these specialty chemicals for prevention and treatment.…more
My current chlorine levels are around 2-3 ppm and pH is 7.4, but I still get green spots forming on the walls every few weeks. The pool guy says algaecides work differently than chlorine, but he couldn't explain exactly how. I'd love to understand the science behind what's happening at the cellular level when algaecide contacts algae, and whether I should be relying more on higher chlorine levels or these specialty chemicals for prevention and treatment.…more


